Metadata Report for BODC Series Reference Number 524204
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags
Metadata Summary
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Problem Reports
The salinity data do not appear credible and have all been flagged suspect.
The absolute attenuance values from this instrument should be used with extreme caution as the record started with unrealistically low attenuance values. Although the values became more realistic with time, the long-term trend in the record should be treated as suspect. The short-term signal on the other hand seems real.
Data Access Policy
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
Narrative Documents
TRB-1 and TRB-2 Self-recording Transmissometers
The TRB-1 self-recording transmissometer was designed by the School of Ocean Sciences, University of Wales, Bangor and was sometimes known as the 'Mark III Transmissometer'. The instrument was developed commercially by W.S. Ocean Systems Limited and marketed with the designation TRB-2.
The instrument used a 660nm (red) source modulated at 400 Hz. The optical assembly incorporated a folded beam design to reduce instrument size to a minimum. The light beam was collimated using an achromatic lens, passed through a fixed length of the water column and reflected back to a photodiode receiver via a prism reflector. The optical path length could be fixed at either 5 cm, 10 cm or 25 cm.
Data were logged at the top of each minute as the average of 200 samples taken at 400 Hz. Timing was based on an accurate real-time clock emulated by the processor BIOS extension. Data were acquired by a multi-channel 12- bit data acquisition system resident on the motherboard resulting in a count between 0 and 4095.
Data were stored internally on a 2 MByte SRAM card giving storage for 120 days of data. After deployment, the data were downloaded in a simple ASCII format onto a PC.
TRB-2 instruments could be fitted with additional conductivity and temperature sensors.
Calibration Details
Introduction
This document covers the calibration details for the TRB2 transmissometer serial number 1761.
Transmissometer
Calibration from raw counts to attenuance was made using the equation:
attenuance= -1/p *ln{(counts-BPR)/(ACR-BPR)}
where:
p = path length (m) = 0.25 m
BPR = blocked path reading (counts) = 31 counts
ACR = air correction reading (counts) = 3237.24 counts
BPR was determined prior to deployment. The instrument was calibrated against fully corrected CTD attenuance data in parallel with the Sea-Tech transmissometers (SN557,SN631 and SN637). Each instrument was strapped to the CTD frame on cast 52 of the cruise Challenger CH140. The CTD was lowered to the sea bed and brought back to 10 metres where it stayed for 30 minutes.
ACR was calculated from the inversion of the above formula using the CTD attenuance data and the corresponding transmissometer counts from the intercalibration cast.
Temperature Sensor
The temperature calibration applied was that supplied by the manufacturer:
Temp (°C)= 18.506785 + 15.381837*X + 1.692264*X2 + 0.527669*X3
where:
X = (2*count-4000)/2000
Conductivity Sensor
The conductivity calibration applied was that supplied by the manufacturer:
Cond (mmho/cm)= 1999.297016 + 878.983174*Y - 79.633062*Y2 - 9.953709*Y3
where:
Y = conductivity channel count
General Data Screening carried out by BODC
BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.
Header information is inspected for:
- Irregularities such as unfeasible values
- Inconsistencies between related information, for example:
- Times for instrument deployment and for start/end of data series
- Length of record and the number of data cycles/cycle interval
- Parameters expected and the parameters actually present in the data cycles
- Originator's comments on meter/mooring performance and data quality
Documents are written by BODC highlighting irregularities which cannot be resolved.
Data cycles are inspected using time or depth series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of adjacent data sets displaced with respect to depth, position or time. Values suspected of being of non-oceanographic origin may be tagged with the BODC flag denoting suspect value; the data values will not be altered.
The following types of irregularity, each relying on visual detection in the plot, are amongst those which may be flagged as suspect:
- Spurious data at the start or end of the record.
- Obvious spikes occurring in periods free from meteorological disturbance.
- A sequence of constant values in consecutive data cycles.
If a large percentage of the data is affected by irregularities then a Problem Report will be written rather than flagging the individual suspect values. Problem Reports are also used to highlight irregularities seen in the graphical data presentations.
Inconsistencies between the characteristics of the data set and those of its neighbours are sought and, where necessary, documented. This covers inconsistencies such as the following:
- Maximum and minimum values of parameters (spikes excluded).
- The occurrence of meteorological events.
This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.
Project Information
PROcesses of Vertical Exchange in Shelf Seas (PROVESS)
Introduction
PROVESS was an interdisciplinary study of the vertical fluxes of properties through the water column and the surface and bottom boundary layers. The project was funded by the European Community MAST-III programme (MAS3-CT97- 0159) and ran from March 1998 to May 2001.
Scientific Rationale
PROVESS was based on the integration of experimental, theoretical and modelling studies with the aim of improving understanding and quantification of vertical exchange processes in the water column, in particular in the surface and benthic boundary layers and across the> pycnocline. PROVESS also explored mechanisms of physical-biological coupling in which vertical exchanges and turbulence significantly affect the environmental conditions experienced by the biota with particular reference to aggregation, flocculation, sedimentation and trophic interactions.
Fieldwork
The experimental phase of the project was carried out at two contrasting sites in the North Sea: the northern North Sea site (NNS) and the southern North Sea site (SNS).
The two sites had the following characteristics:
SNS | NNS | |
---|---|---|
Position | 52° 15.0' N, 4° 17.0' E | 59° 20.0' E, 1° 00.0' E |
Time of year | April-May | September-November |
Water depth (m) | 16 | 100 |
M2 max amplitude (m s-1) | 0.75 | 0.15 |
Max current (m s-1) | 1.0 | 0.6 |
Delta T (deg C) | mixed | 7-1 |
Thermocline depth (m) | mixed | 35-100 |
Delta S | 1 | small |
Halocline depth (m) | 5-10 | cf. thermocline depth |
Max wind speed (m s-1) | 20 | 25 |
Max wave height (m) | 5 | 10 |
Max wave period (s) | 8 | 10 |
Internal motion | No | Yes |
Sediment | muddy-sand | muddy-sand |
Biology | eutrophic | oligotrophic |
At both locations measurements were concentrated at a central position with additional measurements being made to estimate horizontal gradients. Moored instruments (including current meters, temperature and pressure sensors, fluorometers, transmissometers, nutrient analysers and meteorological sensors) were deployed between 7 September and 5 November 1998 at the NNS and between 29 March and 25 May 1999 at the SNS. Each experiment was supported by intensive measurement series made from oceanographic ships and involving turbulence dissipation profiler CTD, particle size profilers, optical profilers, benthic sampling and water bottle sampling.
Details of the cruises were as follows:
Site | Ship (nationality) | Cruise Mnemonic | Date |
---|---|---|---|
NNS | Valdivia (GER) | VA174 | 5 - 17 Sep 1998 |
Dana (DK) | D1198 | 14 - 26 Oct 1998 | |
Pelagia (NL) | PE125 | 19 - 30 Oct 1998 | |
Challenger (UK) | CH140 | 22 Oct - 9 Nov 1998 | |
SNS | Pelagia (NL) | PE135 | 29 Mar - 9 Apr 1999 |
Mitra (NL) | MT0499 | 19 - 30 Apr 1999 | |
Belgica (BE) | BG9912 | 17 - 21 May 1999 |
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 1998-09-09 |
End Date (yyyy-mm-dd) | 1998-10-26 |
Organization Undertaking Activity | Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool) |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | POLRIG#798 |
Platform Category | subsurface mooring |
PROVESS Project POLRIG#798
This mooring was also known within PROVESS as 'Rig I'. It was one of a cluster of moorings deployed at the main focus of the Northern North Sea Site in the autumn of 1998. The rig was deployed by FS Valdivia (cruise #174) in September 1998 and recovered by RRS Challenger (cruise #140) in October/November 1998.
Mooring type | Surface environmental mooring with 1.9 m toroid |
---|---|
Instruments | TRB2 transmissometer 1 m below surface DML fluorometer 1 m below surface NAS nitrate analyser 1 m below surface NIOZ fluorometer 15 m below surface |
Related Data Activity activities are detailed in Appendix 1
Cruise
Cruise Name | VLD174 (PROVESS N-1) |
Departure Date | 1998-09-05 |
Arrival Date | 1998-09-17 |
Principal Scientist(s) | Gunther Krause (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research) |
Ship | Valdivia |
Complete Cruise Metadata Report is available here
Fixed Station Information
Fixed Station Information
Station Name | PROVESS Northern North Sea Site |
Category | Offshore area |
Latitude | 59° 18.00' N |
Longitude | 1° 0.00' E |
Water depth below MSL | 110.0 m |
PROVESS Northern North Sea Site
Nineteen mooring packages were deployed at PROVESS Northern North Sea site during the cruise Valdivia VA174 in September 1998. The layout of the mooring assemblage was L-shaped. It consisted of an heavily-instrumented site centred close to 59° 20' N, 1° 00'E (Site A with rigs A, B, Ca/b, D, E, Fa/b, G, H, I, J1, J2 and L) and secondary single-rig sites extending up to 40 km north (V and Y) and east (U and X). An addition mooring package, NIOZ or Rig M, was also deployed at Site A during the RV Pelagia PE125 cruise in October 1998.
Rigs Ca/b and Fa/b were two short-term rigs which were recovered at the end of the cruise VA174 and redeployed during the cruise Challenger CH140 in October. All the other rigs were recovered during the cruise CH140 in October-November 1998 apart from rigs H and L which could not be found and rig Cb which was trawled and recovered from Peterhead (Scotland).
The layout of the mooring array was:
Mooring data
The data returned from each rig were as follows:
Rig identifier | Data | |
---|---|---|
A | POLRIG#790 | ADCP currents Water level Near-bed temperature |
B | POLRIG#791 | ADCP currents Near-bed temperature |
Ca | POLRIG#792 | Near-bed temperature |
Cb | POLRIG#808 | Rig trawled, no data returned |
D | POLRIG#793 | Currents Temperature, salinity and attenuance |
E | POLRIG#794 | Currents |
Fa | POLRIG#795 | Currents |
Fb | POLRIG#809 | |
NIOZ | Unknown | Thermistor chain |
G | POLRIG#796 | Meteorology |
H | POLRIG#797 | Mooring lost, no data returned |
I | POLRIG#798 | Surface attenuance, nutrients and chlorophyll |
J1 | POLRIG#799 | Mid-water attenuance, nutrients and chlorophyll |
J2 | POLRIG#800 | Near-bed attenuance, nutrients and chlorophyll |
L | POLRIG#801 | Mooring lost, no data returned |
R | POLRIG#802 | Water column temperature |
S | POLRIG#803 | Water column temperature |
U | POLRIG#804 | ADCP currents Water level Near-bed temperature |
V | POLRIG#805 | ADCP currents Near-bed temperature |
X | POLRIG#806 | Water level |
Y | POLRIG#807 |
CTD data
A total of 352 CTD casts were also collected during the four cruises surveying this area. These include:
Cruise identifier | Cruise dates | No. of CTD casts |
---|---|---|
FS Valdivia (#174) | 05 September - 17 September 1998 | 168 |
Dana (#1198) | 14 October - 26 October 1998 | 51 |
RV Pelagia (#125) | 19 October - 30 October 1998 | 73 |
RRS Challenger (#140) | 21 October - 11 November 1998 | 60 |
Additonal data
Complementary meteorological and sea state data for PROVESS Northern North Sea Experiment were obtained from Marine Weather Stations located on Beryl and Frigg oil platforms in the Northern North Sea.
Related Fixed Station activities are detailed in Appendix 2
BODC Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
Flag | Description |
---|---|
Blank | Unqualified |
< | Below detection limit |
> | In excess of quoted value |
A | Taxonomic flag for affinis (aff.) |
B | Beginning of CTD Down/Up Cast |
C | Taxonomic flag for confer (cf.) |
D | Thermometric depth |
E | End of CTD Down/Up Cast |
G | Non-taxonomic biological characteristic uncertainty |
H | Extrapolated value |
I | Taxonomic flag for single species (sp.) |
K | Improbable value - unknown quality control source |
L | Improbable value - originator's quality control |
M | Improbable value - BODC quality control |
N | Null value |
O | Improbable value - user quality control |
P | Trace/calm |
Q | Indeterminate |
R | Replacement value |
S | Estimated value |
T | Interpolated value |
U | Uncalibrated |
W | Control value |
X | Excessive difference |
SeaDataNet Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
Flag | Description |
---|---|
0 | no quality control |
1 | good value |
2 | probably good value |
3 | probably bad value |
4 | bad value |
5 | changed value |
6 | value below detection |
7 | value in excess |
8 | interpolated value |
9 | missing value |
A | value phenomenon uncertain |
B | nominal value |
Q | value below limit of quantification |
Appendix 1: POLRIG#798
Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
541951 | Fluorescence or pigments | 1998-09-09 08:00:00 | 59.3228 N, 1.0108 E | Valdivia VLD174 (PROVESS N-1) |
541963 | Fluorescence or pigments | 1998-09-09 08:00:00 | 59.3228 N, 1.0108 E | Valdivia VLD174 (PROVESS N-1) |
541914 | Water column chemistry | 1998-09-09 10:08:40 | 59.3228 N, 1.0108 E | Valdivia VLD174 (PROVESS N-1) |
Appendix 2: PROVESS Northern North Sea Site
Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
529208 | Meteorology -meteorological data buoy | 1998-09-06 12:42:00 | 59.3435 N, 0.9955 E | Valdivia VLD174 (PROVESS N-1) |
518087 | Hydrography time series at depth | 1998-09-07 10:30:27 | 59.332 N, 1.6715 E | Valdivia VLD174 (PROVESS N-1) |
517766 | Hydrography time series at depth | 1998-09-07 11:40:00 | 59.333 N, 1.4178 E | Valdivia VLD174 (PROVESS N-1) |
518106 | Hydrography time series at depth | 1998-09-07 11:40:27 | 59.333 N, 1.4178 E | Valdivia VLD174 (PROVESS N-1) |
524935 | Currents -subsurface Eulerian | 1998-09-07 11:45:00 | 59.333 N, 1.4178 E | Valdivia VLD174 (PROVESS N-1) |
541883 | Currents -subsurface Eulerian | 1998-09-08 06:59:13 | 59.3312 N, 1.001 E | Valdivia VLD174 (PROVESS N-1) |
524173 | Hydrography time series at depth | 1998-09-08 07:05:00 | 59.3312 N, 1.001 E | Valdivia VLD174 (PROVESS N-1) |
517729 | Hydrography time series at depth | 1998-09-08 09:10:00 | 59.3283 N, 1.0037 E | Valdivia VLD174 (PROVESS N-1) |
518118 | Hydrography time series at depth | 1998-09-08 09:10:27 | 59.3283 N, 1.0037 E | Valdivia VLD174 (PROVESS N-1) |
524947 | Currents -subsurface Eulerian | 1998-09-08 09:14:59 | 59.3283 N, 1.0037 E | Valdivia VLD174 (PROVESS N-1) |
517730 | Hydrography time series at depth | 1998-09-08 11:35:00 | 59.3237 N, 1.0013 E | Valdivia VLD174 (PROVESS N-1) |
524923 | Currents -subsurface Eulerian | 1998-09-08 12:22:30 | 59.3257 N, 0.9998 E | Valdivia VLD174 (PROVESS N-1) |
517742 | Hydrography time series at depth | 1998-09-08 12:30:00 | 59.3257 N, 0.9998 E | Valdivia VLD174 (PROVESS N-1) |
518099 | Hydrography time series at depth | 1998-09-08 15:10:26 | 59.75 N, 1.0013 E | Valdivia VLD174 (PROVESS N-1) |
541951 | Fluorescence or pigments | 1998-09-09 08:00:00 | 59.3228 N, 1.0108 E | Valdivia VLD174 (PROVESS N-1) |
541963 | Fluorescence or pigments | 1998-09-09 08:00:00 | 59.3228 N, 1.0108 E | Valdivia VLD174 (PROVESS N-1) |
524751 | Currents -subsurface Eulerian | 1998-09-09 10:05:00 | 59.3202 N, 1.0003 E | Valdivia VLD174 (PROVESS N-1) |
524763 | Currents -subsurface Eulerian | 1998-09-09 10:05:00 | 59.3202 N, 1.0003 E | Valdivia VLD174 (PROVESS N-1) |
541914 | Water column chemistry | 1998-09-09 10:08:40 | 59.3228 N, 1.0108 E | Valdivia VLD174 (PROVESS N-1) |
524775 | Currents -subsurface Eulerian | 1998-09-09 12:26:00 | 59.3183 N, 0.9998 E | Valdivia VLD174 (PROVESS N-1) |
524799 | Currents -subsurface Eulerian | 1998-09-09 12:26:00 | 59.3183 N, 0.9998 E | Valdivia VLD174 (PROVESS N-1) |
517754 | Hydrography time series at depth | 1998-09-09 16:30:00 | 59.5767 N, 0.9933 E | Valdivia VLD174 (PROVESS N-1) |
524959 | Currents -subsurface Eulerian | 1998-09-09 16:35:00 | 59.5767 N, 0.9933 E | Valdivia VLD174 (PROVESS N-1) |
541975 | Fluorescence or pigments | 1998-09-09 18:00:00 | 59.3292 N, 1.0088 E | Valdivia VLD174 (PROVESS N-1) |
524185 | Currents -subsurface Eulerian | 1998-09-09 18:05:04 | 59.3292 N, 1.0088 E | Valdivia VLD174 (PROVESS N-1) |
553128 | Water column chemistry | 1998-09-09 19:39:23 | 59.3292 N, 1.0088 E | Valdivia VLD174 (PROVESS N-1) |
524197 | Currents -subsurface Eulerian | 1998-09-10 09:45:04 | 59.3262 N, 1.0112 E | Valdivia VLD174 (PROVESS N-1) |
541987 | Fluorescence or pigments | 1998-09-10 10:00:00 | 59.3262 N, 1.0112 E | Valdivia VLD174 (PROVESS N-1) |
517613 | Hydrography time series at depth | 1998-09-10 12:25:00 | 59.3333 N, 1.0833 E | Valdivia VLD174 (PROVESS N-1) |
517625 | Hydrography time series at depth | 1998-09-10 12:25:00 | 59.3333 N, 1.0833 E | Valdivia VLD174 (PROVESS N-1) |
517637 | Hydrography time series at depth | 1998-09-10 12:25:00 | 59.3333 N, 1.0833 E | Valdivia VLD174 (PROVESS N-1) |
517649 | Hydrography time series at depth | 1998-09-10 12:25:00 | 59.3333 N, 1.0833 E | Valdivia VLD174 (PROVESS N-1) |
529233 | Hydrography time series at depth | 1998-09-10 12:25:04 | 59.3333 N, 1.0833 E | Valdivia VLD174 (PROVESS N-1) |
517650 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
517662 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
517674 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
517686 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
517698 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
517705 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
517717 | Hydrography time series at depth | 1998-09-10 14:20:00 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
529221 | Hydrography time series at depth | 1998-09-10 14:20:04 | 59.3742 N, 1.0 E | Valdivia VLD174 (PROVESS N-1) |
564231 | Hydrography time series at depth | 1998-10-21 14:11:54 | 59.3175 N, 1.0087 E | RV Pelagia PE125 |
524787 | Currents -subsurface Eulerian | 1998-10-24 09:44:00 | 59.312 N, 0.9967 E | RRS Challenger CH140 (PROVESS N-4) |
524806 | Currents -subsurface Eulerian | 1998-10-24 09:44:00 | 59.312 N, 0.9967 E | RRS Challenger CH140 (PROVESS N-4) |